Synthesis and characterization of fluorene end-labeled polymers prepared by nitroxide-mediated polymerization

The fluorene-based alkoxyamine 9-(2,2,6,6-tetramethyl-4-hydroxypiperidinyloxy)fluorene was prepared and investigated as a unimolecular initiator in the nitroxide-mediated polymerization (NMP) of styrene. Reactions performed in either bulk or ethereal solvents at 125 degrees C generated polymers possessing low polydispersity indices (PDIs) and number average molecular weight (Mn) values close to those anticipated based on monomer-to-initiator ratios. A linear relationship between monomer conversion and Mn values was observed by analysis of reaction aliquots with H-1 NMR and gel permeation chromatography (GPC), while PDI values remained low throughout. Analysis of the polymers by UV-vis spectroscopy indicated that approximately 80% of the polymer chains were labeled with the fluorene chromophore, while fluorescence spectroscopy was used to verify that the fluorene was polymer-bound. (C) 2008 Elsevier Ltd. All rights reserved.